Optical instrument



H. l..4 DE zENG'. A OPTICAL' INSTRUMENT.

,l APPLICATION mso :UNE 9. lazo:

EABLYBQ. Patented 90151091922 2 SHEETS-SHEET '1.

INMENITOR v H. L. De ZEN G 4 ATTO H. L. DE ZENG'.

GPTICAL lNSTRUM-EI. `APPLICATION FILED JUNE 9, 1920.

Patented Oct.- 10, 1922.

2 SHEETS-SHEET 2.

INVENTOR H. I De Z ENG- -have" ,bring the Aa short necked instrument.

Figure I. i i s Figure III represents a plan view of the i gear side of the'blase plate of the casing.

Patented Oct. 10,` 1922.

IABIJSZ 4 UNITED; 4dSTAras PATENT OFFICE.

HENRY L. DE ZEG, OF MOORESTOWN, NEW JERSEY.

orTIcAr. INSTRUMENT.

Applicationled` June 9, 1920. Serial No. 387,687.

To all whom t may concern: l

Beit known that I, HnNRir L. DE ZENG, a citizen of the United States, residing 'at Mfoorestown, inthe countyof Burlington and State of New Jersey, have invented certain new and useful :Improvements in Optivcal Instruments,y of which the following is al specification. e A Y i Thisinvention relates to improvements in optical instrumentsand hast particular reference to an 'improved form of instrument for viewing the interior of the eye andv measuring its refraction, such as an ophthalmascope. l

i The principalobject of the present inven- Other objects and. advantages of my improved construction include the `simplification of 'parts andthe various structural features and details by which the foregoing advantages may be accomplished in a practical manner, as should be apparent by reference to the following specification taken in connection with the accompanying drawings, in which` thepreferred form of thefinstrument .andl its parts are shown and described for the sake of illustration, but it willbe understood that I may make any modicationsiin the specific detailseof construction shown and described within the scope of the appended .claims without departing from or exceeding vthe spirit of the invent-ion. y

Figure I represents a frontl view of an "ophthalmascope embodying myinvention.

Figure II represents a side elevationfof Figure IV represents an end view or side inside. of the gear cover.,` Y Figure VII represents'a `plan view of the which the oculist or Aan `opening in the instrument into the paelevation of Figure III, vshowing detached segments of the mirror holder. e IvFigure V' represents a back view of Figure Figure VI represents a plan view of the outside of Figure VI. e

Figure VIII represents an vation of Fi ure. VII. i I

Figure I represents a `diagrammatic front view of the lens containing discs removed from the casing.

Figure X shows plan, side and top views of the strap for retaining the mirror in end or side eleplace. of observation for the observer and yet .f

Figure XI represents a front andv end view l of the mirror.

Figure XII represents an, enlarged cross section through'the gear casing and light conducting channel showing the details of 'p construction of `the gear arrangements and `lighting system.

In. instruments for examing the eye, in observer looks through tients eye at the same time reflecting a beam 'of light into the patients eye for illuminavrtion thereof, great difficulty has been encountered owing to the restrictedmangle of vision which the observer is able to obtain due to the fact that the bulk ofthe parts of the instrument removes the eye of the obi server quite a distance from the front of the instrument and the surface of the reflector,

j the situation being perfectly analogous to a l view` obtained through a key-hole, the closer "the eye to the key-hole the wider the angle of observation on the other side, so it is with vthe ophthalmascope of like nature.

fhaveimproved 'by reducing the and other instruments In my present invention I these conditions materially distance between the back and vfrontof the instrument to a minimum ,andto an extent never hitherto obtained as p far; asI am aware, in an electrically lighted yinstrument of this nature.

Another serious objection to instruments of this nature is that heretofore there has time have obtained a wider angle of observa-- tion. v

It is a well known fact that the surfaces of lenses when exposed are hard to keep' clean. They blur readily unless kept covered and away from dust, soot or othei for? eign matter. They not only are apt to become soiled very easily, requiring' constant attention, but also the dustparticles are liable to scratch and otherwise injure the surfaces of the lenses. In instruments hitherto produced, wherein lenses are carried in revolving disks the rotation of the disks has been effected through 'comparatively large openings in the sides of the case through which dust' or other foreign matter might reach the lenses. In my invention Illia-ve devised means for providing a dust proof case over the lens holders allowing onlythe lens under immediate observation to be eX- posed and at the same time I provide more accessible means for driving the lens holders.

Referringto'the drawings in which similar `characters of reference are employed to denote corresponding parts, throughout the i; I y i means of gears,-, best illustrated in Figure I,

several views, the following is a `description and method of operation of the preferred form of my invention which is described by way of illustration.

The instrument illustrated comprises lenses,lens holding and driving mechanism, peepl hole arrangements, illuminating guide and reflector, anda handlefcontaining a source of electric energy. The instrument is built'up around the base plate l, Figure III, which has an opening or` orifice 2 thro-ugh which the operator looks into` the ,patients eye. On the operators side of the instrument, which is the left hand side in Figure XII, the lens holders 3 and 4 are rotatably mounted: on the pivot 5 in such a way `that the individual lenses may be brought in turnv before theorilice 2 in the ybas'e plate.

The len'sholders consi-st of two independ- .ent gear driven discsB and 4. The lenses 16 inthe disc 3 are positive in character except that vone or more lenses ot' the opposite character are introduced atthe endlof thetrain v'andthe lenses f7 in the disc 4 are negative in `character exceptv at the end of the train one or more lensesof oppositie character are introduced. In order that the powers of the lensesY in the discs 3 and 4 may be indicated atv a centralpoint, a portion 8 of the Vdisc 3 is arranged to coineiiush with'the outer face 'the disl 4. This portionS of the disc 3 isunited therewith by means of screws 9 and it will be* seen that the portion 8 forms a y the bushing sary. Y

bushing or bearing for the disc 4. Between 8 andthe pivot 5 the bearing support l() is introduced, tending to act as a distant piece between the base plate and the cover plate. A washer member Il is inserted between the discs 3 and 4 to keep them separated to the` desired distance and prevent theirrubbing one on theV other, also to provide clearance for the lenses when necesllie iowers ofthe lenses in the two rings are in icated around the line of sepa-ration between the face 8 of the disc 3 and the face of the disc the r`powers indicated on the disc 4 running from I to`7 negative power, and having positivepowers 8 and y16 introduced at the end 'of the train, and the powers vis no lens inserted, leaving a clear opening through the two lensy discs. Then in operation the powers of the lenses in the two discs are viewed through a key-hole shaped openfing l2 in the cover plate 13, Figures VI and VII, the negativepowers for convenience of observation being indicated in one color, say red, andthe positive powers in another color, say white.

The lensdiscs are` independently driven by the upper gearfturning the negative lenses in the disc 4 and the lower one turning the o tedoii thebase plate by means of the pivot. 21 which passes through the distance pieces `22 and 23 y respectively:

By turning thedrivingwheel 2O the intermediate idler wheel 18is turned, which in turnV drives the gear Vwheel turning .the posi- 4tive lenses into position beforetlie orifice 2.

By turningthe gear 4wheel I5 thelens disc 4 is immediately engaged and driven, thus Yturning the negative lenses before; the orifice 2. Held inrplace by the pivot 16 is a spring` iinger'24 which acts'as a spring tension member on the gears, as indicated at the point 25 in 4Figure XIII. .l OnV the outer .face ofthe cover plate ,13,f the character .of the Vlenses AV,turned byA the corresponding gear wheels is indicated, the wheel l5, Figure I, being indicated by the negativeV sign 26. and the wheel y20 by,the positive sign 2,7.r

. ,It will be'notedthatthe lower portion of r4the" cover plate and the base plate are cut away so as to allow the driving gears 1 5 and 20 to extend out beyond. This gives room fornthe fingers to engage them and turn the gear wheels to drive the respective lens discs. Itwill also be noted in Figures II and VIII -that the cover plate 13 has a flange 2S surrounding the lens discs, the only place the lenses may be seen being at the key-hole opening l2. This arrangement provides simple means of accessibility to the driving gears and makes a dust proof ca-se for the lens dises.

The illuminating system consists of a light channel or guide 29 secured to the patients side of the instrument, as at 30. At the outer end of this channel is a lens 3l'for focusing the light rays from the source of illumination on a slotted mirror 32 shown in detail in Figure XI. This mirror is arranged in inclined position so as to direct the beam of light from the illuminating channel to the patients eye, the slot 33 being in line 1 with the orifice 2 in the base plate l. The

mirror32 is held in place byl means of the U-shaped strap 34 shown in detail in Figure X, which is screwed over the upper end of the channel portion and held in place by the screw 35, the mirror being held in the slot 36 at the upper end of the channel portion, see Figure IV. The strap 34 holds the mirror in place in this slot.

It will be noted in FigureIV as indicated by Vthe dot and dash lines and the arrows,

that the light conducting channel is placed at an angle to the base plate as indicated by 3T, Figure IV. This inclination of the light channel to the base plate is most important as 1t permits the mirror to be brought up to l -the nearest possible position to the lenses Vand also allows additional room between the gear portion and the handle portion, permitting adjustment of the light. It alsoA permits the observer to look slightly under the reflection, it being noted in this connection that the axis ofthe light channel being at `an angle to the gear case will have a different angle of reflection `in the patients eye than it would have if the axis of the channel were parallel with the gear case as best shown in Figure XII.

The light conducting channel 29 consists of a tube having `aninternal light'passage way and an external boss or attaching portion which is inclined with respect to the ini ternal light passage way. Thisboss or attaching portion is for attachment to the supporting plate by means of the rivet 30.v This light conducting channel is attached `to the handle or battery portions by means of a recessed shoulder or flange portion 51 at its lower end, the recessed flange portion starting at the shoulder 52. The inclination be- -tween the internal light passage way andthe `external attaching portion is of the `first importance because it permits the light to be di- 65.,

rected directlyto the peeping oriceinstead of being oflset by the thickness of theattaching portion orthe thickness of the tube were 'the light passage way parallel with the supporting plate. By this inclination and conducting the light at an angle to the supporting plate the thickness of the instrument or the distance between thei eye of the observer and the eye of the patient is materially reduced;

The source of the illumination is in the handle 38, which consists of the usual battery and bulb connection being shown at 39, Figure XII.4 The light from the electric bulb is thrownI on or off by means of the switch 4() shown in Figure II. l

The operation, which has been explained in detail in the foregoing description, is in brief as follows: The electric'bulb is illu- 'minated by means of the switch 40, throwying the 'light up through the channel 29 to the reflector-32, and thence onto `the patient-s eyes. The eye of the operator is applied to `the oriice2A on the lens side of the instru- 'ment and the instrument is moved up closely lto the `eye of the patient so that the opera- -tor may observe the interior 'of the eye by fmeans of the illumination reflected into it; ythen the lenses in the lens discs lare rotated -by the operator through the wheels 15 and I20 until the object in the patients eye be- {comes perfectly clear. The powers of the :lenses are indicated by the power scales in tithe key-hole shaped orifice 12 in the cover plate, the algebraic sum of the two powers indica-ted representing the sum of the test power. i

As regards the reflection from the slotted mirror into thepatients eye, it will be noted -that by controlling the angle of axis of the lLlight channel 29 to the base plate the angle fof 'reflection of the light may Vbe varied to suit thedesires of the operator and to bring --the reflected light into the actual position "required, 1

It will also be'seen that by throwing in the axis of the light channel at the top the mirrow may be brought closer to the base `Vplate; hence the distance between the opera- `l-tors eye 'and the reflector may be materially reduced, thus allowing him'a considerably increased angle of observation over the olderA instruments. y

tFrom the above description'it will be seen 'lthat I have provided in an instrument of this kind, extremely simple means of obtaining La wide angle ot observation with ample iroom for 'light adjusting means, also of rotating the lenses, of protecting the lenses -from dust and foreign matter, and of rel,ducingethe `size of the instrument, and a simple yet complete lens system. Having described my invention, whatI 'claim is: l y

l. Ina device of the character described,

the combination with a supporting plate element having a sight orifice, a rotating lens element, and a light passageway element superimposed one on the other in immediate contact and in substantially parallel alinement, the lens dial element being pivoted on one side of the supporting plate and adapted to align the lenses successively with the sight orifice and the light passage way element being rigidly secured to the other side of the supporting plate, said light passage way element being provided with a source of' light and an inclined mirror having an orifice in line with the orifice of the supporting plate and inclined `outwardly and upwardly from its point of connection with the supporting plate.

v 2. In a device of the characterk described, the combination of a continuous supporting element having a sight orifice therethrough and a continuous light passage way element substantially parallel therewith and secured thereto and inclined slightly outwardly and downwardly therefrom, said light passage way element comprising a light tube, -a source of light therein, a mirror having an orifice in line with the orifice of the supporting plate and inclined from its point of connection with the supporting plate outwardly `and upwardly therefrom, the elements being so arranged that the patients eye may be placed immediately next tothe orifice yplate in the mirror on one side and the operators immediately neXt the orifice in the supporting plate on the other side.

3. In a device of the character described, a straight continuous supporting plate havyingian orifice and a light tube having its outer surface parallel to and in immediate contact with the supporting plate and secured thereto, and having its inner surface linclined downwardly and outwardly from vthe supporting plate, alight in the tube, and

`a mirror with an orifice in line with the orifice of the supporting plate at the end of the ltube and inclined outwardly and upwardly from the supporting plate.

2. In a device ofy the character described, a casing having an orifice, a pair of superimposed rotatable lens discs mounted in the casing and adapted to align with the orifice, a portion of the inner disc extending through the outer disc, a scale `on the outer extension of the inner disc adjacent its line vof separation from the outer face of the outer disc, and a scale on the face of the outer disc adjacent the scale on the extension, saidv `scales indicating the powers of the lenses in the lens discs.

1 5. In a device of the character described,

ya `pair of rotatable lens discs, a-hub on one of the lens discs on which the other disc is mountedto rotate, a scale on the face of the hub indicating the power of the lenses in the hub' disc, and a scale on the face of the mounted disc indicating the-powers of the lenses in said disc, the two scales being separated by the line of the hub bearing.

6; In a device of the character described, a casing having an orifice, a pair of rotatable lens discs mounted in the casing adapted to bring the lenses in alinement with the orifice, a hub on the inner disc extending through the outer disc, a scale on the hub, a scale on the outer disc adjacent the first scale, said scales indicating the powers of the lenses in the discs, a gear surrounding the outer disc, a finger gear meshing therewith, a gear surrounding the inner disc, an idler gear meshing therewith, and a finger gear meshing with the idler gear.

7. In a device of the character described, a casing having an orifice, a pair of rotatable lens discs mounted in the casing adapted to bring the lenses in alinement with the orifice, a hub on the inner disc extending through the outer disc, a scale on the hub, a scale on the outer disc adjacent the first scale, said scales indicating the powers of the lenses in `the discs, a gear surrounding the outer disc,

a finger gear meshing therewith, a gear surrounding the inner disc, an idler gear meshing therewith, a finger gear meshing with the idler gear, and a spring detent engaging the first finger gear.

8. In a device of the character described, a casing having an orifice, a pair of rotatable lens discs mounted in the' casing adapted to bring the lenses in alinement with the orifice, a hub on the inner disc extending through the outer disc, a scale on the hub, a scale on the outer disc adjacent the` first scale, said scales indicating the powers of the lenses in the discs, a gear surrounding the outer disc, a finger gear meshing therewith, a gear surrounding the inner disc, an idler gear meshing therewith, a finger gear meshing with the idler gear, an inclined tube on the back of the casing, a reflector having an orifice in alinement with the orifice in the casing, and a lamp in the inclined tube.

9. In a hand supported ophthalmological instrument, a hand holding portion comprising a handle, a handle supporting part, a light passage way chamber, an attaching portion yarranged at an angle to the hand holding portion, and a base plate secured to the attaching portion of the hand holding element.

10. In a hand supported ophthalmological instrument, the combination of a base plate portion inclined thereto, and a detachable In testimony whereof I have aiiixed my joint between the light chamber and the signature, in presence of two witnesses. hand supporting portion, and e base plate secured to the external attaching portion, HENRY L' DE ZENG said base plate and said hand holding ele- Witnesses: ment being inclined at an angle one to the S. W. CAFFERTY,

other. v LYDIA H. LYoNs. 

